This study investigated the word recognition processes of readers of Chinese as a native language (L1) and as a second language (L2), focusing on the effects of two factors, word familiarity and word structure difficulty (complexity of orthographic symbol), on reading accuracy and response time. Subjects were in three groups: (1) 14 adult native Chinese readers; (2) 14 high-proficiency L2 readers; and (3) 14 intermediate proficiency L2 readers. All subjects completed a context-free word recognition task on computer, matching a character seen only briefly with one of four characters shown afterwards. There were 192 trials in the experiment. All words used were selected according to printed frequency (high/low) and orthographic structure (simple/complex as represented by number of strokes). As anticipated, the high-frequency words were processed faster than the low-frequency words. Orthographic complexity alone did not necessarily affect L1 readers' word recognition but did strongly affect L2 readers' word recognition, especially among less-proficient readers. Contains 17 references. (MSE)